1. Field of the Invention
The present invention relates to a light source adjusting technique. More particularly, the present invention relates to a light source apparatus and a light source adjusting module.
2. Description of Related Art
FIG. 1 is a block diagram illustrating a light-emitting device applying a MR16 halogen lamp. Referring to FIG. 1, a power supply 110 provides an alternating current (AC) voltage signal (for example an 110V AC voltage signal). Next, a phase modulator 120 modulates a conducting phase of the AC voltage signal. An electrical transformer 130 transforms the modulated 110V AC voltage signal to the 12V or 24V AC voltage signal for outputting to an MR16 halogen lamp 140, so as to lighten the MR16 halogen lamp 140. Since the AC voltage signal generated by the electrical transformer 130 contains light-adjusting data, it may adjust a luminance of the MR16 halogen lamp 140. Therefore, in the light-emitting apparatus of FIG. 1, the luminance of the MR16 halogen lamp 140 can be adjusted by controlling the conducting phase of the AC voltage signal, so as to achieve a light-adjusting effect.
Though the halogen lamp has an advantage of high luminance, it also has disadvantages of high power consumption, short lifetime and high temperature, etc. With development of technology, light emitting diodes (LED) having features of long lifetime, high efficiency, light-weighted, etc. are developed. Therefore, the MR16 halogen lamp can be substituted by the LED, so that the MR16 lamp apparatus may share the advantages of the LED.
FIG. 2 is a block diagram illustrating an MR16 light-emitting device applying an LED. Referring to FIG. 2, functions of a power supply 210, a phase modulator 220 and an electrical transformer 230 of FIG. 2 is the same to that of the power supply 110, the phase modulator 120 and the electrical transformer 130 of FIG. 1, and therefore detailed descriptions thereof will not be repeated. A difference between FIG. 2 and FIG. 1 is that the light-emitting devices connected to the electrical transformers are different. In FIG. 1, the electrical transformer 130 is connected to the MR16 halogen lamp 140, and in FIG. 2, the electrical transformer 230 is connected to a bridge rectifier 240, a driver 250 and an LED 260. Namely, the bridge rectifier 240 receives the 12V or 24V AC voltage signal generated by the electrical transformer 230, and rectifies the AC voltage signal into a direct current (DC) voltage signal. Then, the DC voltage signal is provided to the driver 250 to drive the LED 260, so that the LED 260 may generate a light source. The bridge rectifier 240, the driver 250 and the LED 260 form a light-emitting module, and a lamp head utilized by the light-emitting module is complied with an MR16 specification.
However, the conventional driver 250 cannot detect the conducting phase information of the AC voltage signal modulated by the phase modulator 220. Namely, the driver 250 cannot control the luminance of the LED 260 according to the conducting phase information modulated by the phase modulator 220. Therefore, to control the luminance of the LED 260, extra pins are added to the driver 250, and a variable resistor VR is connected. Next, by adjusting a resistance of the variable resistor VR, the luminance of the LED 260 can be adjusted. However, such structure is different to the MR16 lamp apparatus specification (since the pins required for connecting the variable resistor are added), so that the original MR16 lamp apparatus specification cannot be directly applied to the LED 260, and therefore utilization thereof is inconvenient.